Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: kagliostro on June 28, 2024, 02:10:18 pm

Title: 5C1 with recovered material - V1 question
Post by: kagliostro on June 28, 2024, 02:10:18 pm: A friend has build, with old parts, a 5C1 amp

this is the schematic

(https://i.imgur.com/y5n0hY4.jpeg)

The output level is satisfying if he uses a Signal Generator at the input, but is low if he use the guitar

There is way to arrange components aroud V1 (6B8 - he has a glass version of the tube) as to increase his output to the Power Tube ?

http://frank.yueksel.org/sheets/021/6/6B8.pdf (http://frank.yueksel.org/sheets/021/6/6B8.pdf)

Thanks

Franco
Title: Re: 5C1 with recovered material - V1 question
Post by: sluckey on June 28, 2024, 02:20:01 pm: Replace the 6B8 with a 6SJ7 and follow this schematic...

https://el34world.com/charts/Schematics/files/Fender/Fender_champ_5c1_schem.pdf
Title: Re: 5C1 with recovered material - V1 question
Post by: kagliostro on June 28, 2024, 02:25:24 pm: :l2: :l2: :l2:

OK

Franco
Title: Re: 5C1 with recovered material - V1 question
Post by: uki on June 28, 2024, 05:31:29 pm: What kind of pickups on the guitar? Some pickups have lower output than others, try another guitar?
Title: Re: 5C1 with recovered material - V1 question
Post by: kagliostro on June 28, 2024, 05:58:29 pm: Right it must be considered

Franco
Title: Re: 5C1 with recovered material - V1 question
Post by: kagliostro on June 29, 2024, 03:46:29 am: Seems that also a guitar with active pickup was tried without the desired result

I think he must swap V1 for one other tube or insert a gain stage (jfet) between input and V1

Franco
Title: Re: 5C1 with recovered material - V1 question
Post by: jeff on June 30, 2024, 05:30:05 am: Dumb question, but, are the batteries in active pickups dying?
Sometimes the littlest things get overlooked.
Title: Re: 5C1 with recovered material - V1 question
Post by: kagliostro on June 30, 2024, 07:27:52 am: Don't know, I'll ask

Franco